1. Technical Field
The present invention relates to an optical disc apparatus, and more particularly to an optical disc apparatus having the function of monitoring a current flowing in an actuator provided in an optical pickup.
2. Description of the Related Art
JP-A-9-305981, JP-A-2006-79783, and JP-A-7-129978 describe conventional optical disc apparatuses. JP-A-9-305981 discloses that when the optical disc apparatus detects an unlocked state of a focus lock, and a focus search operation and a focus pull-in operation are performed, the position of an objective lens included in the optical disc apparatus is controlled and an optical pickup included in the optical disc apparatus moves to the position of an original track. The position of the objective lens is controlled to prevent the objective lens from moving toward an optical disc lest the objective lens collides with the optical disc. JP-A-2006-79783 discloses that an objective lens is positioned with a gap between the objective lens and a recording surface of an optical disc when a laser beam is turned off and an operation for a focus servo is not performed during loading or unloading of an optical disc. In the technique described in JP-A-2006-79783, after the optical disc is loaded and it is confirmed that a rotation speed of a spindle motor reaches a predetermined rotation speed, the laser beam is turned on. After that, a collision avoidance mode is released and a focus search operation starts. In order to unload the optical disc, the focus servo and a tracking servo are turned off. Then, the collision avoidance mode is turned on. After that, the laser beam is turned off and the rotation of the spindle motor is completely stopped. The operation for unloading the optical disc then starts. When it is confirmed that the optical disc moves to a safe location at which the optical disc does not collide with the objective lens, the collision avoidance mode is released. The optical disc apparatus described in JP-A-7-129978 detects that an objective lens comes too close to an optical disc during an operation for controlling a focus servo in order to prevent an optical head and the optical disc from colliding with each other when a vibration or a shock occurs. When the objective lens comes too close to the optical disc, the objective lens is forcibly driven to move away from the optical disc.